BMW working on small electric bike
Although BMW has been at the forefront of electric motorcycle development for over a decade - initially with the C Evolution scooter and now with the CE-04 - the company has yet to launch a battery-powered motorcycle. A new patent revealing designs for a small electric motorcycle using powertrain parts from the CE-04 could change that.
Focus might have been on scooters so far, but BMW's electric plans also include 'real' bikes. Not only has BMW shown several electric concept bikes over the years, but it also trademarked a whole run of model names for production versions, each starting with 'DC'. So while future electric BMW scooters will have 'CE-' followed by a number, the electric motorcycles will use 'DC-' and a number. The number appears to roughly approximate the capacity of equivalent combustion engine models, so the CE-04 has similar power to a 400 cc scooter.
If that's the case, the bike seen in the latest patent could well be the 'DC-04', because it appears to use the same battery and motor as the CE-04, but cleverly repositioned into a much more compact, motorcycle-shaped package.
The motor itself is turned 90 degrees so its shaft runs longitudinally rather than across, reducing the vehicle's width, and the motor is then tilted to around a 45-degree angle in the chassis. It drives the front sprocket via a bevel gear that doubles as a reduction ratio, with a belt final drive and larger rear sprocket adding a second layer of reduction to bring the high-speed electric motor down to an appropriate range for the wheel.
Like the motor, the battery pack looks to be the same unit used in the CE-04, but again, it's mounted at an angle, parallel to the motor and fitting neatly behind the front wheel and below the 'fuel tank' - which is now an empty storage compartment that appears easily big enough to swallow a full-face helmet. The charging and electronic control circuits are split into two main units, one mounted below the transmission, the other sandwiched between the drive motor and the battery pack. Again, these parts look very similar to the equivalents used in the CE-04, but have been moved to suit their new home.
Overall, the bike appears to be the same size as the G310R, with a similar swingarm, rear shock and seat. That would suit the 400 cc-equivalent performance of the CE-04 motor, which is good for a peak power of 31 kW (42 hp) - a worthwhile step up from the 25 kW (34 hp) achieved by the G310's single-cylinder, 313 cc engine. Like the G310, the bike could easily be adapted to multiple roles without changing the main components. The ICE model is already sold as the G310R roadster, the G310GS adventure bike and the G310RR sports bike, so if this patent is pursued, it could instantly create a whole range of BMW EV motorcycles without requiring the expensive development of any new driveline parts.
